In view of the inherent contradiction between mass data and real-time browsing in Highway 3D Visualization System, this paper proposes an edge folding algorithm for weighted average elevation base on vertex degrees, which will improve the model simplification effective. In the process of building a continuous LOD model, the algorithm uses mesh line to blocky process the terrain model to eliminate the adverse effects of long and narrow triangles, adopts Hoppe’s reversible progressive meshes construction algorithm to build grid-based LOD terrain model of continuous reversible, finally adopts LOD scheduling algorithm based on viewpoint, realizing multi-resolution terrain display of continuous reversible.